tdf#104495: prevent autotext to crash when drag&drop

See bt https://bugs.documentfoundation.org/attachment.cgi?id=129407

For non regression, I retested tdf#91125 since the delete comes from
https://cgit.freedesktop.org/libreoffice/core/commit/?id=06ecf7d2aebe64226142ee27c2512351960f8bb1

Change-Id: I7ce833ffce20f1f159242014ba8ffe0ce5b7b11c
Reviewed-on: https://gerrit.libreoffice.org/31773
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Maxim Monastirsky <momonasmon@gmail.com>

svtools/source/contnr/treelistbox.cxx

@@ -1178,7 +1178,6 @@ void SvTreeListBox::StartDrag( sal_Int8, const Point& rPosPixel )
     {
         nDragDropMode = nOldDragMode;
         DragFinished( DND_ACTION_NONE );
-        delete pContainer;
         return;
     }